The Spitfire Mark VIII was to have been the main production version powered by Merlin 61 series of engines. However, development work took time, and it was not until November 1942 that the first production Mk VIII was flown – nearly half a year after the interim (and highly successful) Mark IX had scored its first victory. In the event, Mk VIII was vastly overshadowed by the latter, its more numerous sibling.The three main sub-variants of the Mark VIII, according to altitude rating of the engine, were: the standard F (Fighter) Mk VIII powered by the Merlin 61 and 63 engines, LF Mk VIII for low altitude work with Merlin 66, and the high-altitude HF Mk VIII equipped with Merlin 70. Mark VIII featured enlarged engine cowling designed to take the new, two-stage supercharged Merlin, strengthened airframe, twin radiators under the wings, four-bladed propeller and retractable tailwheel. Early-production Mk VIIIs retained the Spitfire’s standard rounded fin and rudder tip, which was later replaced by the broad-chord, pointed-tipped rudder (due to the torque produced on take-off by the new, powerful engine). Some early Mk VIIIs featured the extended wingspan of 40’2” with distinctive, pointed wingtips (later models had the standard span of 36’10”, or were clipped to 32’2”). Mark VIII was developed in parallel with Mark VII, the only major difference being the pressure cabin of the latter.Fitted with the ‘C’ type wing, Mark VIII was armed with two 20 mm Hispano cannon and four 0.303 in Browning machine guns (each cannon had 120 rounds of ammunition, the Brownings each having 350 rounds). It could also carry up to 1,000 lb of bombs on wing shackles (2 x 250 lb) and under fuselage (500 lb). Notably, Mark VIII incorporated the compact Vokes ‘Aero-Vee’ tropical filter as standard, which (unlike the earlier, chin-type seen on the Mark Vc trop) did not affect the aircraft’s performance. Overall, 1,658 Spitfire Mark VIIIs were produced.Spitfire Mark VIII saw extensive overseas duty. In the Mediterranean Theatre of Operations, No 145 Sqn RAF went operational on Mk VIIIs in June 1943, prior to the invasion of Sicily. In Italy (and later in southern France) the Mk VIII was flown by the British, Canadians, South Africans and the Free French, as well as Americans (namely 31st Fighter Group USAAF, until it converted to P-51 Mustangs in April 1944). Most of these units simultaneously operated the Mk VIII and IXs.In the Far East, Nos 81 and 152 Sqns RAF became operational with Mk VIIIs in India in December 1943. By June of 1944 seven more RAF squadrons based in the China-Burma-India Theatre of Operations had converted to Mk VIIIs, and another two in early 1945.In the Pacific, No 1 Fighter Wing (at that time composed of Nos 54, 548 and 549 Sqns RAF), converted to Mk VIIIs in April 1944. They took over the defence of Darwin area, allowing Australian Spitfire squadrons to move on to Netherlands East Indies. The No 80 Fighter Wing RAAF, formed in mid-May 1944, was initially composed of Nos 452 and 457 Sqns (transferred from No 1 Fighter Wing), which were joined by No 79 Sqn in February 1945.